The present invention relates to a light weight responsive tilt ramp rodent trap.
FIGS. 7 and 8 show a typical prior art tilt ramp trap. This trap is of the type manufactured under the trademark TIN CAT(copyright) by Woodstream Corporation, Lititz, Pennsylvania 17543. The prior art trap is designated generally by the numeral 100. It includes a box 102 which encloses a trap compartment 104. Providing entrance into the trap compartment 104 is a mouse hole 106. Within the box 102 is a tube 107 having a tube entrance opening 108 adjacent the mouse hole 106 and having a tube exit opening 110 providing communication into the trap compartment 104.
Within the tube 107 is a tilt tramp 112. Tilt ramp 112 pivots about a ramp or pin axis 114 and includes an entrance end 116 and an exit end 118. A counter weight 120 is provided on the entrance end 116 to bias the tilt ramp 112 to the position shown in FIG. 7.
A flap 122 is pivoted about a pivot pin 124 and rests by gravity on the entrance end 116 of tilt ramp 112.
When a mouse enters into the mouse hole 106, the mouse M proceeds up the ramp, and when the weight of the mouse at 1{fraction (5/16)}th  inches from the pivot point or pin axis 114 exceeds 7 grams, the ramp tilts downwardly to the position shown in FIG. 8. At the same time the flap 122 pivots upwardly in response to frictional engagement with the end 116 of tilt ramp 112.
The above prior art device has several shortcomings. The weight of 7 grams at a distance of 1{fraction (5/16)}th  inches from the fulcrum or pin axis 114 of the tilt ramp 112 is sufficient to cause the ramp to tilt in response to a full sized adult mouse, but is insufficient to tilt in response to a lighter weight of an immature mouse. Thus younger mice can proceed up the ramp without tilting the ramp and escape merely by returning down the ramp.
This responsiveness to 7 grams of weight is the result of several factors. One factor is the chosen weight of the counterweight 120. Another factor is the friction between the flap 122 and the entrance end 116 of the tilt ramp 112. As can be seen in FIG. 7, the flap 122 rests with its face in full engagement with the upper surface of the tilt ramp 112, and this adds to the friction required in order to tilt the tilt ramp 112. Also, there is a need to reduce the friction caused by pin axis 114 and the pivot pin 124.
Therefore, a primary object of the present invention is the provision of an improved light weight responsive tilt ramp rodent trap.
A further object of the present invention is the provision of a light weight responsive tilt ramp rodent trap which includes a tilt ramp that tilts in response to a weight of 4 grams at a distance of 1{fraction (5/16)}th  inches from the fulcrum of the tilt ramp.
A further object of the present invention is the provision of an improved light weight responsive tilt ramp rodent trap which includes dimples and tabs for engaging the flap as the tilt ramp pivots about its tilt ramp axis, thereby reducing the friction between the flap and the tilt ramp.
A further object of the present invention is the provision of an improved hinge for the tilt ramp which reduces the friction necessary to cause the ramp to tilt.
A further object of the present invention is the provision of an improved hinge for the flap which reduces the friction necessary for the flap to pivot in response to the tilting of the tilt ramp.
A further object of the present invention is the provision of an improved counter balance which reduces the force necessary to tilt the ramp.
A further object of the present invention is the provision of a trap which includes tubes for the mouse to enter which are connected to the top wall of the trap and are pivotal to a position wherein the tubes are outside the trap for cleaning of the trap.
A further object of the present invention is the provision of an improved rounded corner on the inside of the trap box to facilitate cleaning.
A further object of the present invention is the provision of elongated ribs on the top wall of the box for improving the strength thereof.
A further object of the present invention is the provision of an improved light weight responsive tilt ramp rodent trap which is economical to manufacture, durable in use, and efficient in operation.
The foregoing objects may be achieved by a rodent trap comprising a box having a top wall, a bottom wall, end walls, a front wall, and a rear wall enclosing a trap compartment. There is at least a first mouse opening in one of the front, rear, and side walls of the box and an elongated tube is provided within the trap compartment. The tube includes a first open end in communication with the first mouse opening and includes a second end. An elongated tilt ramp is within the tube and includes an entrance end adjacent the mouse opening of the box and also includes an exit end adjacent the exit opening of the tube.
A hinge pivotally mounts the tilt ramp within the tube for tilting movement about a hinge axis from a first position wherein the entrance end is adjacent the bottom wall of the box adjacent the mouse opening and the exit end is elevated above the entrance end, to a second position wherein the exit end is lowered from the first position.
A flap is provided on the exit end of the tilt ramp. The flap being in covering relation over the exit opening of the tube when the tilt ramp is in its first position and being removed from covering relation over the exit opening of the tube when the tilt ramp is in its second position.
A biased member is connected to the tilt ramp and biases the tilt ramp to its first position. The biased member yields in response to a weight of a mouse adjacent the exit end of the ramp to permit the tilt ramp to move to its second position. The tilt ramp is moveable from its first position to its second position in response to a downward force of 4 grams at a point between the hinge axis and the exit end of the tilt ramp and located 1{fraction (5/16)}th  inches from the hinge axis.
According to another feature of the invention the biased member comprises a weight attached to the tilt ramp.
According to another feature of the invention the flap is hinged about a horizontal flap axis and is engaged by the entrance end of the tilt ramp. The flap pivots about its flap axis in response to movement of the tilt ramp from its first position to its second position.
According to another feature of the invention the tilt ramp includes cam surfaces projecting upwardly therefrom adjacent its entrance end. The cam surfaces bear against the flap before moving the flap about its flap axis during movement of the tilt ramp from its first to its second position.
According to another feature of the invention the tilt ramp includes angular tabs projecting from the entrance end of the tilt ramp. These angular tabs engage the flap during movement of the tilt ramp from its first position to its second position.
According to another feature of the invention the top wall is hinged to the box for movement from an open position providing axis to the trap compartment to a closed position enclosing the trap compartment. The tube in the tilt ramp are carried by the top wall of the box for movement therewith in responsive to movement of the top wall from its open to its closed position.
According to another feature of the invention the tube includes a top wall and an angular flange extending downwardly therefrom. The flap engages the angular flange when the tilt ramp is in its second position to close the first open end of the tube.